: i'm want to kill some noise from a drum practice room.
: 3 walls are 3/8" drywall on wooden studs and one wall
: (exterior) is 8" block. will installing 5/8" (one or
: 2 layers)drywall over everything give me the best bang
: for the buck? will installing insulation above the
: ceiling further reduce noise to the floor above?
The methods you suggest will have little effect on your noise levels because the noise levels are so high. The EPA manual we sell on the website contains info that is essential to planning a sound reduction project or you may, like many, find you've done too little, too late! Check out the article on the site about soundproofing a garage, too!